The subtitle says all how it helps, “In-kind advertising for non-profit organizations [1].”
If you are part of a 501(c)(3) NPO, read the detail about applying [2], then go ahead to apply [1]. Google Grants offers at least three months with a cap $10K per month free advertising via AdWords to awarded organizations [3].
They also created a blog [4] for giving information about the program, tips of using AdWords and helpful documents, etc. You can also ask on Google Grants Help.